Refrigeration



VE-1 9 I A. R. THOMAS 2,293,522

REFRIGERATION Filed Jan. 9, 1940 I Ill l I l l/ /l l/ I storage compartment I9.

Patented Aug. 18, 1942 UNITED STATES PATENT OFFICE REFRIGERATION Albert R. Thomas, Evansville, Ind., assignor to Serve], Inc., New York, N. Y., a corporation of Delaware a heat transfer system embodying the invention.

Cooling element III represents a source of re frigeration. It is shown as an evaporator of a uniform pressure absorption type refrigeration system like that described in my application Serial No. 107,852, filed October 2'7, 1936, now Patent No. 2,207,838. In the evaporator I0 is a pipe coil II. Liquid refrigerant enters the upper part of evaporator Ill through a conduit I2. Inert gas enters the upper part of evaporator I8 through a conduit I3 and a cylinder I4 which is within the pipe coil II. Gas leaves the evaporator Ill through conduit I5. Liquid refrigerant from conduit I2 flows into a distributor I Ii. Liquid is deposited from distributor I6 onto the top of coil II. The liquid refrigerant flows downward over coil II and evaporates and diffuses into the gas, producing a refrigeration effect for cooling the coil II.

The upper end of coil II is connected by a conduit I I to the top of a vessel I8. Vessel I6 is located in the upper part oi? a refrigerator The lower end of coil II is connected by a downwardly looped conduit 20 to the bottom of a vapor lift vessel 2|. The top of vessel 2| is connected by a conduit 22 to the upper part of vessel I8. The upper end of a finned evaporator coil 23 is connected to the upper part of vessel I8. The lower end of evaporator coil 23 is connected to the lower part of vessel I 8. Vessel I8 forms a header for coil 23. Evaporator coil 23 is located in the upper part of refrigerator compartment I9 and is used to cool air in this compartment during operation of the system as hereinafter described.

The bottom of vessel I8 is connected by a conduit 24' to the lower part of a vessel 25. Vessel 25 is also located in refrigerator compartment I9 but at a level below that of vessel I8. Conduit 24 juts downward in'vessel 25 and is open at its lower end near the bottom of vessel 25. The upper end of a, finned evaporator coil 25 is connected to the upper part of vessel 25. The

Application January 9, 1940, SerialNo. 313,052 5 Claims. (Cl.62 125) and more the lower part of vessel 25. Vessel ,25 forms a header for coil 25. Evaporator coil 26 is located below evaporator coil 23 in the refrigerator compartment I9. Whereas evaporator coil 23 and its header I8 are located in the top of refrigerator compartment I9, coil 26 and its header 25 are located in the bottom of compartment I9. The top of header 25 is connected by a conduit 2'! to a nozzle 28 which juts upward in vapor lift vessel 2|.

Coil II and evaporators23 and 26 together with the above described connections therebetween form a heat transfer system which is evacuated and charged with'a suitable heat transfer fluid, such as methyl chloride. When the refrigeration apparatus is started, the evaporator I 0 lowers the temperature of coil II, causing a reduction in'pressure in this coil and also in conduit I1, vessel I8 and conduit 22. Due to this reduction in pressure, liquid evaporates in coil 23 producing a cooling effect for cooling air in compartment I9. .Vapor flows from the upper end of coil 23 into vessel I8, and thence through conduit Hi to the condenser coil II. Vapor is condensed to liquid in coil II. The liquid flows from the lower end of coil II into conduit 20,

lower end of evaporator coil 26 is connected to vessel 2i, and the lower part of conduit 22.

Liquid also evaporates in evaporator coil 26. The vapor flows from the upper end of coil 26 into vessel 25. Vapor in vessel 25 is segregated from the condenser II in one direction by a liquid trap seal formed by liquid in the bottom of vessel 25 and conduit 24. In the other direction, vessel 25 is cut off from the condenser by liquid in conduit 20, vessel 2I and the lower part of conduit 22. Vapor in the upper part of vessel 25 therefore exerts a pressure on liquid in the lower part of this vessel, causing it to rise or back up through conduit 24 into vessel I8, establishing a liquid column of height H.

Vapor flows fromthe top of vessel 25 through conduit 27 and issues through nozzle 28 in vessel 2!. The vapor issuing from nozzle 28 becomes trapped in liquid in the lower part of conduit 22,causing the column of liquid in this conduit to become lighter than the column of liquid in conduit 22. The column of liquid and gas in conduit 22 therefore increases in height until it reaches the upper end of conduit 22 where it overflows into'vessel I 8. The liquid flows into the lower part of vessel I8 while the vapor joins vapor from evaporator 23 and flows through conand the surface level of liquid in conduit 20, and

both columns H and 1-1 should equal the height oi. the gas and liquid column extending from nozzle 28 to the upper end of conduit 22.

The pressure in evaporator 26 is greater than the pressure in evaporator 23 by the height of the liquid column H, so that evaporation takes place in coil. 26 at a correspondingly higher temperature than in coil 23. Evaporation of liquid in coil 26 aids in cooling compartment 69. It may be used to pro-cool air circulating over the main coil 23. The vapor produced in coil 25 is used for causing circulation of liquid in the heat transfer circuit as described. This vapor is: at alrigher pressure than that from coil 23 so that less vapor is required for the lifting action than it the lifting vapor were supplied by evaporator 23. The arrangement also permits the low temperature evaporator to be located in the very top of the refrigerator compartment iii for most effective cooling of air in this compartment and without the requirement of apparatus projecting above the top of the refrigerator. also evaporotor 23 is connected directly to tr e condenser coil it so that cooling of the refrigeration systerr the refrigerator it subeta" perature loss as far as e cerned. "With respect to ev tion takes place a also takes place at a hiu vapor is required ior iii liquid through a certain heig efficiency or. a heat transfer is increased.

Various changes and modifications may be made within the scope of the invention as set forth in the following claims.

What is claimed is:

l. A heat transfer system including a closed circuit forvolatile fluid having a plurality of places of evaporation, a place of condensation at a level below said places of evaporation, and a bubble type vapor liquid lift for raising liquid a 2. A heat transfer system as set forth in claim 1 in which said higher place oi evaporation is in the upper part or" a refrigerator storage compartmerit and said lower place of evaporation is in a lower part of said compartment.

3. A heat transfer system including a closed circuit for volatile fluid having a first evaporator, a second evaporator below said first evaporator, a conduit for liquid from said first evaporator to said second evaporator having a liquid column forming trap, a condenser below both said evap craters, a vapor liquid hit for delivering liquid to said iii st evaporator, a conduit for liquid from said condenser to said lift, and a conduit for vapor from said second evaporator to said liit.

i. A heat transier system as set forth in claim in which said first and second evaporators are ted in the top and bottom respectively of a storage compartment.

A retired of heat transfer which includes laces at different elevations, condensing vaporous refrigerant to hcguid below said places of evaporation, raising condensed liquid by vapor bubble lifting action to said places of evaporation, utilizing for said lift action vapor from one of said places of evaporation which is at a level below another of said places of evaporation, and causing the vapor in said first place of evaporation to be at a pressure above that in said second place of evaporation by maintaining a column of liquid between said places.

ALBERT R. THOMAS;

iorating lidiid refrigerant in a plurality of 

